They are beings with human and demonic decent, born through rape. One of their parents is a demon and the other is a human. The human "parent" are usually women and any women pregnant with a forsaken child will die as the child will rip out of the women's stomach.

All forsaken are sterile unable to have children, the population of forsaken is large as new forsaken are born almost everyday. They are immortal and cannot die of old age but can still be killed.

A Forsaken's powers come from the mixture of human and demonic blood. However, Forsaken have no human souls nor human blood in them. Thus, they are forced to drink the blood of humans, because of this they are often mistaken for Vampires.

They are the main enemies of the Shadowchasers the battles between them are usually are won by the shadowchasers.

Forsaken seem like beautiful humans, until they invoke their demon form, or seen by clear-sighted beings. They have snake-like teeth that retract to the roof of their mouths. They also use these teeth to drain blood from their victims.

Another common trait is that their nails are sharpened to points, sharp enough to cut flesh without much force.

One final trait is that their pupils are slits, one horizontal and one vertical.